49.    neither, either

A. 1.     neither means 'not one and not the other'. It takes an affirmative singular verb. It can be used by itself or followed by a noun or by of + the/these/those/possessives or personal pronouns:

(a)  I tried both keys but neither (of them) worked.

(b)  Neither of them knew the way/Neither boy knew . . .

(c)  I've read neither of these (books).

2.     either means 'any one of two'. It takes a singular verb and, like neither, can be used by itself or followed by a noun/pronoun or by of + the/these/those etc.

3.     either + negative verb can replace neither + affirmative except when neither is the subject of a verb. So either could not be used in (a) or (b) above but could in (c):

I haven't read either of these (books).

Though either cannot be the subject of a negative verb, it can be subject or object of an affirmative or interrogative verb:

Either (of these) would do.

Would you like either of these?

4.     Pronouns and possessive adjectives with neither/either used of people should technically be he/him, she/her and his/her, but in colloquial English the plural forms are generally used: Neither of them knows the way, do they? Neither of them had brought their passports.

B.     neither . . . nor, either ... or

neither . . . nor + affirmative verb is an emphatic way of combining two negatives:

(a)  Neither threats nor arguments had any effect on him.

(b)  They said the room was large and bright but it was neither large nor bright.

(c)  He neither wrote nor phoned.

either ... or + negative verb can replace neither . . . nor except when neither . . . nor is the subject of a verb, as in (a) above. So:

(b)    ... but it wasn't either large or bright and

(c)  He didn't either write or phone.

either ... or cannot be the subject of a negative verb but can be the subject or object of affirmative or interrogative verbs and is used in this way to express alternatives emphatically:

You can have either soup or fruit juice, (not both)

You must either go at once or wait till tomorrow.

It's urgent, so could you either phone or telex?